I'm fairly sure WBZ will stay All-News from 5am to 7pm weekdays and till 5 or 6 on weekends. David says WBZ has seen its billings drop and its demos rise over the years. But it is still a big billing station in Boston, perhaps the only significant biller on AM. I think I read that it's #3 in morning drive. Those demos may be old because it has no FM simulcast. (BTW, iHeart's KFBK Sacramento has a 20,500 watt FM simulcast now.)
I would imagine iHeart will negotiate with SAG-AFTRA for WBZ's employees. Probably those already working for the station will keep most of their pay and benefits but maybe new hires will not get the same deal. Again, I'm pretty sure nearly all current employees will stay. There may be a few positions where iHeart wants someone already with the company to move in, but only a few.
The cuts to the WRKO staff may be more significant. A few years ago, Entercom didn't want to pay Rush's fees anymore. It put a local host in his time slot, making the station all-local from 6am to 7pm (although it runs paid financial shows in late morning). Evenings are syndicated. WRKO runs Dave Ramsey at 7pm (which will probably be pushed later), Jim Bohannan at 10pm (a Westwood One show... probably not staying), Beyond Reality at 12am (also syndicated...probably not staying) and Coast to Coast AM (a Premiere show...so it will be staying). I'm sure iHeart will run Rush live at noon, it will likely keep its morning show and probably delay Hannity for evenings. I believe Howie Carr is too popular to ax or move to evenings, so it will be Hannity that has to wait till 7pm for airing.
iHeart's WOR in NYC is a similar mix of syndicated and local. Local from 5am to noon and 6pm to 9pm. Syndicated the other weekday hours. And the weekends are nearly non-stop infomercials around the clock. WOR staffs its newsroom 24/7. It runs no network newscasts. Same for KFI LA. But I'd guess WRKO will pick up Fox News, in which iHeart has a financial stake. Fox News is running every hour on 1430 and someone above says iHeart is selling 1430.